1. Field of the Invention
The present invention relates generally to ski boots and specifically to an improved ski boot including an inflexible rigid sole and a shaft arranged immovably relative to the sole and including further a circular roll off area located at said sole to facilitate the walking with the ski boot and defining the heel thereof.
Ski boots are presently customarily made of a plastic material. Such boots comprise an inflexible rigid shaft which is immovably connected to a rigid and commonly flat planar sole. Because such rigid connection blocks the ankle, it is quite inconvenient to walk with such a boot. In order to improve the stability of the skier on his skis the shaft is usually inclined forwardly relative to the sole by an angle generally known as "forward lean angle". Such a boot is still worse regarding a walking therein.
2. Description of the Prior Art
In order to facilitate the walking with rigid ski boots it has already been proposed to form the shoe sole cambered in the longitudinal direction thereof. Accordingly when the wearer of such ski boots is walking, the shoe can roll off on the cambered sole and, therefore, the tibia can easily be bent relative to the knee. This indeeds allows an improved walking with the shoe; however, if the wearer stands still, the shoe will rock on its standing surface.
It has been suggested further to shape a portion of the cambered sole as a flat planar standing area. Such a boot incorporates in the center section of its sole a standing area which at the front and at the rear passes into a respective roll off area. Such a shoe is disclosed in the CH-PS No. 609 541. It is possible to walk and to stand safely with such shoe, but the standing area interrupts and disturbs a smooth rolling off of the sole at its standing area during the walking motion. It also has been found that when wearing this boot vertical movements, specifically of the ankle, are carried out during the rolling off movement of the sole such that at each step the body of the wearer rises and descends. These continued rocking motions of the center of gravity of the body of the wearer are quite tiresome when walking with these boots.
The U.S. Pat. No. 4 505 057 discloses a ski boot having a circular roll off area acting as heel of the boot which indeed does facilitate the walking; however, the vertical rocking movements of the ankle of the wearer are not obviated therewith.
It is generally known that when walking barefooted the ankle is not subjected to horizontal rocking movements and the smooth swinging movement of the tibia will not be disturbed by the standing area of the foot.